Raise your hand if you think that the 1949 Stags (a fine team no doubt) would be favored to beat the 2015 New York Knicks!

The problem is that ELO is constrained to an average value of 1500 over time, thus removing the signal of any trends, variability or non-stationarity in the league performance.

ELO is a tool for contemporary comparison, and is not well suited for presentation as a time series because the baseline changes over time. I'd guess over the long term it has changed so that teams get better, on average, as compared with those of the past. But certainly there is variation in the overall competitive level of the league, which ELO does not capture.

So when 538 says that the 1996 Chicago Bulls were "the best ever there ever was," what this really means is that they were relatively the best team ever, in comparison to the competition that they faced in 1996. That is a bit different than saying they are "the best that ever was." Producing a time series of ELO is thus fundamentally flawed.

In other words, an average ELO team in 2015 at 1500 is not at all comparable to an average ELO team at 1500 in 1949. The 2015 New York Knicks, as awful as there were in 2015, would probably beat the 1949 Chicago Stags by about 100 points.

Thus, rather than reporting absolute ELO scores 538 might have reported anomalies from the long-term average, to present a team's relative ranking, thus removing the need for consideration of any trend. Not as cool as a long-term ranking, but more accurate.

About This Blog

This blog is my professional notebook for commentary and analysis related to sports in society. My main interests are in the governance of international football (soccer), the governance of college athletics and sport as a laboratory for social science research.

In case you are curious I support Arsenal and St. Pauli, and of course, the mighty Colorado Buffaloes.